Suspension & Brakes - Pro-Kit install problem?

Alright guys, maybe someone on here has been through this, so I'm gonna throw it out there and hope somebody bites;

I put eibach prokit spring on my car a few days ago, part #3870140, The rear lowered 1.75" and the front only lowered about .5", actually a hair less. I checked the spring numbers, and they're right (3870.001 front, 3870.002 rear), and I've driven the car for about 20-30 miles so far, with minimal to no change. Any ideas?

I briefly spoke with a tech today, who suggested that it may be because I tightened everything while the car was still in the air, and the struts/springs need to be under load when the bolts are tightened... but that's not making a lot of sense to me... Reused the struts (Koni DAs) so that shouldn't effect it.

When other people put theirs on, did you have to rotate the bottom spring cup/isolater 180 degrees?

I have a hard time believing that I'm missing something, but maybe I am. I've got a new set of springs on order, and they'll go in on Friday, unless I come up with something else beforehand. Anybody?

no idea guy. Sorry. How are you supposed to tighten the hardware while it's under load? :confused: that doesn't make much sense.


My prokit sat fine afterwards. Sorry I can't help. Good Luck!!

That was my question... his response was something to the extent of "if a professional shop was installing them, they would have used an allignment rack to load the suspension before tightening the pivot bolts down". hmmm.....

Never heard of that. My springs looked just fine after install. Is the spring on the cup correctly? That could keep it up higher if not. Other than that I have no idea man. Hope you get it figured out

Never heard of that. My springs looked just fine after install. Is the spring on the cup correctly? That could keep it up higher if not. Other than that I have no idea man. Hope you get it figured out

Ditto... rule out that the springs were seated corretly in the spring cup moldings on the top and bottom.

no idea guy. Sorry. How are you supposed to tighten the hardware while it's under load? :confused: that doesn't make much sense.


Most rubber suspension bushings should be tightened at ride height. That being said, I can't think of anything in an f-body that would be loosened (a-arm or control arm) to install a set of springs. The lower shock mount is not typical due to the bar pin, so it can be tightened pretty much any time the holes line up.

The issue here is there is nothing that needs removed like LCA's where the bushings could bind. Your rear ride height is, unfortunately, not a big surprise with LS1 Pro-kits.... they vary hugely in actual drop. Some are fine, some are far from it.

Up front, you most likely have the springs not seated in the notches for the spring pigtails and that's why the front isn't very low.

eibach tech support is worthless. all they can tell you is whats already written on any documentation that comes with their products.

eibach tech support is worthless. . . . .


and so are their springs . . .